Modern medical imaging assemblies, such as x-ray tubes, are becoming increasingly powerful as their respective technologies advance. In many cases, as the power of these assemblies increases so too does the mass of their respective components. This increase in mass can result in an increase in strain on individual components within the assembly. Components are often joined using bolted joints, which must bear the strain of these increases. The need to accommodate stress and strain increases impacts basic functioning, performance, and precision of the imaging assembly.
Additional complications arise in complex imaging technologies such as computed tomography (CT). Computed tomography assemblies commonly alternate loads and stresses on their components and bolted joints due to starting, stopping, and rotation of the system. This subjects these bolted joints to high and variable loading which in turn makes them susceptible to fatigue. The bolted joints in these systems can be highly critical as they are used to attach imaging devices to the rotating assembly portions of the CT assembly.
It is recognized that fatigue resistance of a bolted joint is primarily driven by the preload applied to the fastener by the torque applied during installation in combination with joint characteristics. Monitoring the real-time force present in a fastener would allow for detection of attachment problems prior to any failure of the system, joint, or component. A multitude of direct load monitoring techniques are known, but require a direct physical connection to the bolt joints. This, in turn, introduces a plurality of additional circuits, cumbersome wiring, complex interference reconfigurations, and increases slip ring issues. Thus direct physical connection monitoring has an undesirably effect of assembly complexity, configuration, and cost.
It would, therefore, be highly desirable to have an assembly for monitoring bolt or other fixture strain in medical imaging assemblies that had minimal impact of assembly complexity, configuration, and cost. Additionally, it would be highly desirable to have such an assembly that could communicate wirelessly between the fixture joints and a remote monitor to eliminate the need for complex wiring configurations.